Simple Solutions That Work! Issue 11

28 Contact: BRODIE BIERSNER [email protected] system would affect heat transfer into the mold. Changing only the part 2 did show an influence on how quickly the heat dissipated from the liquid metal into the molding media. Using a modified part two, the heat flow increased from 3.3 w/g to 4.0 w/g, Figure 4. The mold media temperature curves also showed a change. The influence was not detected readily at the 1/8” location, Figure 5. However, as this heat energy is transferred deeper into the mold, Figure 6, the temperature of the sand mold is higher with the unmodified (original) part 2 into the mold. The modified part 2 preserved more heat in the metal, allowing increased solidification time. CONFIRMATION OF RESULTS Throughout the testing process, pouring temperatures were collected along with cooling curves of the A316 alloy by placing a thermocouple directly into midpoint of the casting. The start of solidification and end of solidification were calculated from the cooling curves. The results of the calculations can be found in Table 1. When reducing the resin from 1.00% to 0.75% using the original PUCB resin package, solidification time was extended by 5.3%. In the experiments using the modified part 2, solidification time was extended by 0.76%. IMPLEMENTING RESULTS INTO PRODUCTION The results from the experiment in the lab confirmed the amount of resin and resin types can change in the amount of energy required to raise the temperature of the sand mold and solidification rate of the alloy. The results from the experiment were implemented into solidification software and a custom data set for the newly developed sand mix was created for the customer. With this new dataset the actual part was simulated and the results from simulation showed that a more sound casting could be found by moving away from the original formulation of 1.00% resin for this particular casting application. The research and simulation results were presented to the customer on how the resin package could influence and reduce the creation of shrink for this particular part. The data and simulation results justified that a change in the resin was required. A production trial was carried out with the PUCB resin based on the research conclusions. A reduction in shrink related defects was immediately found when making an adjustment to the resin. This modification reduced the shrink related defects below the original resin system scrap levels. The change was permanently implemented after the trial. 28 Table 1: Solidification results of lab testing done comparing the original cold box resin package to the modi- fied package. Figure 1: Results of DSC testing to determine heat flow using only the original resin package and modifying resin percentage only. Figure 3: Temperature curve of mold- ing media comparing the original pack- age with a thermocouple placed 1/4” away from the mold/metal interface. Figure 5: Temperature curve of molding media comparing the original package with the modified version us- ing a thermocouple placed 1/8” away from the mold/metal interface. Figure 2: Temperature curve of mold- ing media comparing the effect of res- in reduction using the original formula. The thermocouple was placed 1/8” away from the mold/metal interface. Figure 4: Results of DSC testing to determine heat flow comparing origi- nal package to the modified version. Figure 6: Temperature curve of molding media comparing the original package with the modified version. A thermocouple was placed 1/4” away from the mold/metal interface.